Back-spacing mechanism.



W. W. TORRENGB. BACK SPAGING MECHANISM.

APPL'mATIoN FILED Nov. e. 906.

5v als TTOP/Vy PATENTED APR. 9, 1907.

10.850,106. PATENTBD APR. 9, 1907.

W. w. TORRBNGB.

BAKsPAoIN-G MBG'HANISM. APPLICATION FILED NOV.6.1906.

PATENT i OFFICE.

-WILL'IAM W. roRRENcn OF sonnNEcTADY, NEWl YORK, AssrGNOR, BY Dinner AND MnsNEV ASSIGNMENTS, TO UNDERWOOD TYPEWRITER COMPANY, or New YORK, N` Y., A CORPORATION OF VNew JERSEY.

BACK-SPACING IVIECHANISM.`

Specification of Letters Patent.-

' Patented April 9,1907.

Original application 'led May l16, 1903, Serial N0. 157,417. Continu-ation of abandoned renewal application filed November 29, 1905,

Serial No. 289,867. This application llledNovember 6 1906.v Serial No. 342,303.

To` all wiz/m, it may concer-m '.Be it known that I', WILLIAM llllJlOR-l RENOE, a citizen of the United States, residing in Schenectad in the county of Schenec-- tady and State o' New York, have invented certain new and useful Improvements in Back-Spacing Mechanism for Type-Writers,

of which the following is a specification.

My invention relates to an improvement in type-writers, and has to do more particularly with back-spacingv mechanism adapted for use when it is desired to movel the carriage back a space, or as many spaces as desired for that matter, "the mechanism being a1"- ranged at one side of the keyboard, so that the operator can back-space the carriage by ressing his thumb. against a lever provided.

lor. that purpose without the necessity of reaching out and taking hold of the carriage. With these objects in view th(n invention consists in a rocking leverhaviigj a thumbpiece at one end and a dog pivote ily connect-- ed 'at the other and in position to engage teeth on the carriage-rack, whereby to backlspace the carriage a space at' a time .with

each rocking movement of'the lever.

In'the accompanying drawings, Figure 1 i's a view of a .portion -ofthe type-writer, show'F ing this back spacin thereto..A Fig. 2 1s a p an view. Fig. Sis-.a front View, and Fig. 4 is a view from one side of the machine.

` A re resents the base or'frame of the machine trolled by pinion '1, the teeth o which lnormally engage the teeth of the rack-bar. l

-The numeral-2 indicates a rock-'lever pivotedl in bearings 3 -3 in the'side of thema.-

' Aidog 'orpawl' .with the v-horizontallj' -dispo'sed endof-thi's" chine and provided at one vend with an upturned thumb-piecel at one side of the keyboard-and atthe other en d with an arm,

the extremeupper end of which is bent over .horizontally about Ona preferably "the rackbar C.-

evelwith pivot-ally connected arm by means o fa- 83j-and this Fd'og or pawl is provided wit -a tooth adapted to.' etween ltwo teeth of lthe rack-bar.'

engage This tooth.9 inclines in a dire'c'tiongfto corre- :spond withthe" teeth-of the 'rack-bar to'famechanism .applied is the carriage, Vand C the usual rackbar connected with the oarria `e and con-l cilitate and insure its ventering and fitting therebetween, so that it will take a firm hold I and' retain that hold until the carria eis locked in that'position. The rocking ever is normally heldinward-by' a spiral spring `10, which extends fromthe frame of the machine by the pin 8. A ilat plate-spring 11,'

4secured to the'irame of the machine, presses 1 against the dog or awl andnormally` forces it `towardthe rackar.

pawl, is provided with an inclined surface 13', upon which the beveled end 14 of thel pawl A bracket 12, secured on thera'me of the lmachine'opposite the free end of the'dog or or dog rides whenA the thumb-piece is released, whereby' to throw it outward or forward and its tooth out of engagement with the tooth of the rack-bar. v'An arm' 15 err-*A tends horizontally Jfrom this bracket beneatlr--l the freeend ofgthe dog'or pawlfor the-pulr-f` pose of supportingthe latter at that point.

In operation when the 'operator'. desires to -space the carriage backward' hesimplyf presses With his thumb' Outward -on' 'the thumb-piece. Thisrnoves the dog endwi'se tothe right, and a's it is moved the platesprin tends toisiwing it inward toward the rackar and does swing it inward as the dog .86 l:` recedes .from theinclining-surface 1 3 of the bracket 12, whereuponits tooth enga es be-A tween two teeth of the'rack-ban'andt e iurther. movement ofthe thumb-piece to the vright until -its limit is reached is just sucien't to move the carriage the space of one tooth,

whereupon it is caught'in the usual wayQ.

Then to move it another spaceithis operation .two teeth and thence-outward upon the inf-f;

This'mechanism' is v 1t 1s deslred' toreturn t e carrlage .o

arisin and which ordinaiilyrequiresj-emuc cessitates yreaching out with one or "both -conv'enierit when 'Qrg more spaces, -fwhich exigency 1s, continu l is repeated, the dog vriding back over one' Or'"f" .9"0 v clined4 surface with each return movement'ofj' 'the parts .caused bythe spiral springlO, thus". lthrowing the toothof the dog or pawl out of. the path of therack-teeth so as not to inter'- .y ere with the usual forward spacing operation.

1003i floss o time, and. it is the common' practicefinf- Qback-spacin to take 4hold ofthecarrlageaidg movelt. bodl y, which opera-tion notf'only lne-.

' butwt'he back-spacing 4is done with absolute precision and the position of the hand accurately spea'king, at.`the right-hand end thereof.

Anotherfeature of marked importance is 15 that lthe attachment ma be applied without appreciable alteration o 'the machine.

` `hanges of a more or less slight nature may be resorted to without departure from thespirit and scope of. my invention, and 2.o hence I do not wish to limit m selfto the exa'ctconstruction herein descriged H vingthu's'describcd my invention, I

1. The combination stationary brackethavin'g an inclined surface, and an .outwardly-extending arm, ofa dog or paWl which normally rests loosely upon t e-arm, and pawl which' acts normally to force the latter `g-oagainst the incline to remove the pawl from the toothed bar. y

' 2. The combination with a toothed bar, a

frequently pushing back Without'apreciably changing;l 'moved from the ein its normal place l 1n range' of the keyboard for" the reason the thumb-lever is on. lthe keyboard, or,` more with al toothed bar, a

a spring connected with the stationary bracket having an inclined sur face, andan outwardly-extending arm, of a dog or pawl which normally rests loose] upon the arm, a g spring which throwsit -towardthe incline whereby to remove it from the teeth and means for eausl ing itto engage the toothed bar when reincline.' 3. vThe combination 'with a toothed bar, a

"stationary bracket having anrinciiied surface; and an outwardly-extending arm, of a dog or pai'vl which upon the arm, a spring which the incline whereby to reto engage the toothed bar when removed from the incline, anda rockflever for operatting the dog or paw r 4. The combination with a 4toothed bar, bracketand arm, the bracket havin an inclined surface thereon, of a 'pawl or o con- 'structed and adapted to be moved bac and forth in proxim1ty lto 'the toothed bar, a spring acting to cause the dog or aWl to engage the toothed bar when rection `and the inclined surface When it moves in the other direction, -Which surface removes it from the toothed bar. i

WILLIAM W. TORRENCE. itnesses: FRANCES E.ToRRENcE, K. FRANKFORT.

normally rests loosely in one di- 

